Adjustable choke for double barreled shotguns



c. M. GIBSON 2,731,754

ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS 1950 5 Sheets-Sheet l III! 111 IIQ U Jan. 24, 1956 Filed Feb. 23,

Jan. 24. 1956 c. M. GIBSON 2,731,754

ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS Filed Feb. 25, 1950 5Sheets-Sheet 2 b gwue/wbom CZ 705 M 6/550 C. M. GIBSON Jan. 24, 1956ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS 5 Sheets-Sheet 3 FiledFeb. 25, 1950 CL YDE r7. G/sso/v,

C. M. GIBSON Jan. 24, 1956 ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS5 Sheets-Sheet 4 Filed Feb. 25, 1950 Wow,

Jan. 24, 1956 c. M. GIBSON ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS5 Sheets-Sheet 5 Filed Feb. 23, 1950 IN V EN TOR. CA 705 f7. a/aso/v,

United States Patent ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS ClydeM. Gibson, Huntington, W. Va. Application February 23, 1950, Serial No.145,818

2 Claims. (Cl. 42-79) Another object of this inventoin is to provide anad justable choke device for use with double barreled shotguns, andincluding removable choke sleeve members for each shotgun barrel whichmay be readily removed and replaced independently of each other withoutremoving the entire choke assembly from the muzzle end of the gun. Thispermits part of the assembly to be formed integrally with the gunbarrels, if desired.

Further objects and advantages of this invention will be apparent uponreference to the following specification,

taken in conjunction with the accompanying drawings,

in which:

Fig. 1 is a top plan view of the muzzle end of a double barreled shotgunprovided with the choke assembly of this invention;

Fig. 2 is a horizontal sectional view similar to Fig. 1, but showing inpartial elevation the choke adjusting members and a key device adaptedto actuate individually the choke adjusting members;

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 1; i

Fig. 4 is a transverse sectional view taken on line 4-4 of Fig. 1;

Fig. 5 is a front end elevational view of the muzzle end and chokeassembly shown in Figures 14; a

Fig. 6 is a fragmentary bottom plan view ofthe muzzle end and chokeassembly shown in the preceding figures;

Fig. 7 is a top plan view partly in section of a modified form of chokeassembly, part of which is formed integral with the barrels of a doublebarreled shotgun;

Fig. 8 is a transverse sectional view taken on line 88 of Fig. 7; V

Fig. 9 is a bottom view of the gun barrel and choke assembly taken inthe vicinity of line 8-8 of Fig. 7;

Fig. 10 is a fragmentary vertical sectional view taken on line 1010 ofFig. 7 to show the gun sight in the top of the choke assembly forremovably securing the cam retainer pin of the choke adjusting members;

Fig. 11 is a top plan view of another modified adjustable chokearrangement;

Fig. 12 is a front elevational view of the construction shown in Fig.11;

Fig. 13 is a longitudinal sectional view taken on line Iii-13 of Fig.12;

Fig. 14 is a top plan view similar to Fig. 11 with a portion of theupper part of the housing for the choke adjusting members broken away;and

Fig. 15 is a front elevational View of the construction shown in Fig.14.

Referring to Figures 1-6 of the drawings, the muzzle ends of the shotgunbarrels are shown at 10 and 11 and are provided with a suitably shapedhousing 12 which slides over the muzzle ends of the gun barrels, and hasa pair of internal bores adapted to be aligned with and to formcontinuations of the gun barrel bores, but having larger internaldiameters than said bores. The bores of the housing receive theadjustable and removable choke sleeves 13 and 14 for the respective gunbarrels 10 and 11. The supporting sleeve 12 is secured to the muzzle endof the shotgun by a suitable number of pins 15 and 16 extending throughthe adjacent walls 17 and 18 of the shotgun. Instead of attaching thesupporting sleeve 12 with the pins 15 and 16 as shown, the supportingsleeve section may be secured to the muzzle end of the shotgun bysweating on, by the use of solder, or by screws placed radially aboutthe supporting sleeve 12 so as to grip the muzzle ends of the barrels.In another embodiment of the invention to be described, the sleevesection is formed integrally with the muzzle ends of the shotgunbarrels.

The removable and adjustable choke sleeves 13 and 14 are received withinthe enlarged bores of the supporting sleeve member 12 with the rear endof each sleeve abutting the front end surface of one of the gun barrels10 and 11. The choke sleeves are removably secured in place by aremovable pin 20 extending centrally downwardly through the supportingsleeve section 12 and through correspondingly located slots or notches21 and 22 in the central adjoining wall portions of the choke sleeves 13and 14. The pin 29 is provided with a shouldered head 23 as more clearlyshown in Figs. 3 and 4 and is cut away at 24 and 25 to conform to theinside shapes and diameters of the choke sleeves. The pin Zil may beretained in the choke sleeve securing position by a set screw 26engaging a notch in the countersunk portion of head 23 and threaded intothe fiat central upper portion 27 of sleeve 12.

The removable and adjustable choke sleeves 13 and 14 are identical,since they are to be used with identical twin barrels of a shotgun. Eachsleeve, as in the case of choke sleeve 14, is provided with a pluralityof longitudinal slots 23 extending rearwardly from the forward end ofthe choke. A circumferential groove 29 may be provided on the outsideperiphery of the choke sleeve in a radial plane adjacent the ends of theslots 28 to provide a weakened zone so that the slotted ends of thechoke sleeve will assume a relatively straight taper beginning at theplane of the groove 2?. The forward end of each choke sleeve 13, 14 isalso provided with an external beveled cam surface 30 which is adaptedto cooperate with a complementary beveled cam surface on the chokeadjusting member to be described hereinafter in a manner to causecontraction or permit expansion of the choke.

The adjustable choke sleeves 13 and 14 each operate in conjunction withone of the choke adjusting cam members 35 and 36, which match sleeves 13and 14 in their inner and outer diameters. Each choke adjusting cammember, as in the case of member 36, is provided with a beveled camsurface 37 to fit about and cooperate with the beveled cam surface 39 ofthe corresponding choke sleeve 13, 1d. The front end of each chokeadjusting cam member 35, 36 is provided with a notch 38 to cooperatewith the pin 39 of a removable choke adjusting key 40.

The choke adjusting cam members 35 and 36 are retained within thesupporting housing 12 by a removable cam retaining pin 41 which may, ifdesired, be provided on its upper end with an integral front gunsight42. The cam pin 41 is held in place by a set screw 45 and extendsthrough upper portion 27 of sleeve 12 into cam grooves 43 and 44 in theadjoining walls of the choke adjusting members 35 and 36. These groovesare spirally arranged as shown, so that when one of the members 35 or 36is rotated, it will bemoved forwardly or rearwardly, depending upon thedirection of rotation, to contract or permit expansion of the forwardend of the choke sleeve 13 or 14 with which it cooperates. It isdesirable that one complete revolution of members 35 and 36 will movethese members through the entire range of adjustments. It is clear thatthe engagement of the beveled cam surfaces 30 and 37 at the adjoiningends of the choke sleeves and choke adjusting members cause contractionof sleeves 13, 14 upon rearward movement of members 35, 36, whileforward movement of these adjusting members permits the naturalresilience of sleeves 13 and 14 to open the forward slotted ends ofthese sleeves.

In order to prevent accidental or unauthorized rotation of the chokeadjusting cam members 35 and 36, they are provided with a plurality ofperipheral detent receiving depressions 46 (Figs. and 6) adapted tocooperate with a pair of spring pressed detent balls 47 and 48. Thedetent balls 47 and 4-3 are held in place by a spring clip 49 mounted bya screw on the lower surface of sleeve 12.

Key 40 has a knurled grip 41a, a central portion 41b bearing markings,and a smaller rear end portion adapted to be inserted in either chokeadjusting member 35 or 36. Projection 39 on the key 40 is dimensioned toengage slots 38 so as to rotate the choke member and adjust the choke ofeither gun barrel independently of the other.

In order to remove either of the choke sleeves 13 or 14 it is onlynecessary to unscrew the set screws 26 and 45 and withdraw the removablepins 20 and 41 which will thus permit the choke adjusting members 35 and36, together with the choke sleeves 13 and 14 to be removed axially fromthe muzzle end of sleeve 12. The latter can be removed by taking outpins and 16.

Since the novel arrangement of removable choke sleeve as described aboveenables the ready removal of either or both chokes in a double barreledshotgun arrangement, it is also convenient to form the outer housing ofthe choke assembly integral with the shotgun barrels as shown in Figs. 7through 10 of the drawings. The muzzle ends of the respective barrels 60and 61 of a double barreled shotgun terminate at their forward ends insurfaces 59 and beyond these surfaces they are enlarged as at 62 toprovide a supporting housing with twin enlarged cylindrical bores toreceive removable adjustable choke sleeves 63 and 64, which are ofsimilar construction to the choke sleeves 13 and 1 previously described.The choke sleeves 63 and 64 are retained in the sleeve supporting boresby a pin 65 passing through the upper and lower walls of the enlargedbarrel portion 62 and through corresponding slots or notches in theadjoining walls of the choke sleeves. The central portion of the pin 65is notched on each side to conform to the configurations of the chokebores in a manner similar to the pin previously described. In order toproduce a more aesthetically desirable product, the pin 65 may beretained in place by a countersunk nut 66 at its lower end in thecentral bottom portion of the enlarged gun end section 62.

The choke sleeves 63 and 64 are adjusted by choke adjusting members 67and 63 which are constructed and operate in the manner of the chokeadjusting members 355 and 36 previously described. The adjusting members67 and 63 are retained in place by the cam retaining pin 69 adapted tocooperate with spiral earn grooves in each adjusting member, such as thecam groove '76. The pin 69 may be countersunk in the top rib 7 2 andretained by the threaded gun sight member 73 which abuts the topshoulder surface of the pin 69.

In order to remove or replace either choke sleeve 63 or 64, it is onlynecessary to withdraw the pins 65 and 69 and slide the choke adjustingmembers 67 and 68 together with the choke sleeves 63 and 64 out of theenlarged bores at the front ends of the gun barrels. The adjustment ofthe choke sleeves .63 and .64, one at a time, is effected by anadjusting key similar to the key 40 pre viously described, the members67 and 68 having notches 67 and 68' corresponding to notches 38 in theembodiment of Figs. 1-6. Spring detents, not shown, may also be providedto prevent accidental rotation of the choke adjusting members 67 and 68in a manner similar to that shown in Figs. 4 and 6.

Figs. 11-13 show a modification of the invention in which sleeves 83,slotted at their forward ends at 86, are supported in supporting sleevebores 87 by screw threads 88. This modification also differs in that thechoke adjusting members 89 and 90 have a plurality of cam grooves 91 andthe cam element 92, corresponding in function to elements 41 and 69, hasa plurality of teeth 93 which lie in the grooves 91. The element 92 alsois of different construction in that it has a rearwardly extendingtongue 92a which fits into a depression 94, and through which passes ascrew 95 having an enlarged head to serve as a sight.

In the embodiment shown in Figs. 14 and 15, the choke sleeves may be ofany of the various types shown in the above described embodiments, andthe choke of these sleeves is controlled by choke adjusting members 101,the forward portions of which have external square type threads 102. Theforward end of the housing 103 surrounding the sleeves 100 and members101 has matching internal threads 104 which are approximately half asdeep as the height of threads 102. The threads 102 of the members 101intermesh as shown in the drawings. Top and bottom ribs 105 and 106 areattached to housing 103 as by welding, soldering or other suitable meansfor reinforcement.

The embodiments which I have described thus provide constructions whichare readily assembled and disassembled, and which, by a simpleconstruction, permit the use of different choke settings on each barrelof a double barrelled shotgun. In this way, if desired, one barrel isready for close in shooting, while the other is ready for longer rangework. Or, if desired, both barrels may be set to the same choke setting,or to only slightly different settings.

I am fully aware that variations may be made in the devices which I havedescribed and shown withou departing from the inventive concept, and itis my intention to cover all such variations falling within the scopesof the appended claims I claim:

1. A choke device for a double barreled shotgun, comprising a housingcarried by the muzzle ends of the barrels, said housing having a pair ofbores axially aligned with and forming continuations of the gun barrelbores, but having larger diameters than said gun barrel bores, a. pairof tubular choke sleeves mounted one in each bore of said housing, saidchoke sleeves having axially slotted forward wall portions and camshaped forward end portions, means for retaining said choke sleeves insaid housing, a pair of tubular cam members positioned one in each ofsaid housing bores forwardly of said choke sleeves, said cam membershaving rear cam surfiaces cooperating with the cam shaped forward endsof said choke sleeves-so as to cause contraction of the forward portionsof said choke sleeves on rearward movement of said cam members, ahelical groove in each cam member, and an element located between saidcam members and cooperating with .said helical grooves and with saidhousing for holding said cam members in said housing and for causingaxial movement of the cam members when they are rotated.

2. An adjustable choke device for double barreled shotguns in which thebarrels terminate at their muzzles in forward end surfaces, said devicecomprising a supporting housing carried by the barrels and extendingbeyond said forward end surfaces of the gun barrels, said supportinghousing having a pair of bores aligned with 5 and forming continuationsof the gun barrels, but of greater diameter than said gun barrels, saidhousing having at least one transverse wall, a pair of choke sleeveshaving longitudinally slotted forward end portions terminating inforward cam surfaces, said choke sleeve members being movably positionedone within each of the bores of said housing with the rear ends of thechoke sleeves abutting the forward end surfaces of the respective gunbarrels, said choke sleeves each having at least one opening in theirside walls, at least one removable retaining pin passing between saidchoke sleeves to retain the choke sleeves in their respective supportinghousing bores, said retaining pin extending through said transverse wallof said supporting housing and into said openings in the adjacent wallportions of said choke sleeves, and a pair of cam members positioned onein the muzzle end of each bore of said housing and cooperating with saidcam surfaces to control the bore diameters of the longitudinally slottedends of the choke sleeves, said cam members being tubular and eachhaving a helical groove therein, and a cam member retaining pinextending through a transverse wall of said housing and into the camgrooves of said cam members, whereby said last mentioned retaining pinserves to hold said cam members in said housing and also serves, in (:0-operation with said cam grooves, to translate rotary movement of saidcam members into axial movement of said cam members to cause changes inthe choke of the corresponding choke sleeves References Cited in thefile of this patent UNITED STATES PATENTS

